New lml engine build, no fuel rail pressure

[Toxic]

If you got no injector signal. I'd verify your cam signal is good and in sync with the crank signal. The ECM won't fire the injectors without a CAM signal unless the engine is already running and it looses the CAM signal

I believe it has good cam and crank signals.

 

[Toxic]

 

[2004LB7]

On the last video, can't see which one os actual and which one is commanded fuel rail pressure. But if the lower one is actual then you aren't building pressure. Lost prime or lift pump isn't working if you have one

And fist video, not sure but I'm not seeing much of a CAM signal or count

 

[Toxic]

On the last video, can't see which one os actual and which one is commanded fuel rail pressure. But if the lower one is actual then you aren't building pressure. Lost prime or lift pump isn't working if you have one

And fist video, not sure but I'm not seeing much of a CAM signal or count

Yes the bottom is actual fuel rail pressure. Lift pump works I’ve verified good flow to cp3, 8-9psi also. Lift pump goes straight to cp3. Might try a cam sensor then, pretty cheap.

 

[2004LB7]

Yes the bottom is actual fuel rail pressure. Lift pump works I’ve verified good flow to cp3, 8-9psi also. Lift pump goes straight to cp3. Might try a cam sensor then, pretty cheap.

If that is correct, you aren't building fuel pressure. It will never start with it that low

 

[Toxic]

If that is correct, you aren't building fuel pressure. It will never start with it that low

Yes, I'm aware of that; that's the whole purpose of this thread, trying to figure out why it won't build any rail pressure.

 

[2004LB7]

I'd double check you have the feed going to the correct port on the CP3

 

[JoshH]

Did you ever check to make sure the regulator on the rail isn't dumping fuel back into the return while cranking? That's usually what I see is the main problem when the LML trucks aren't building rail pressure. It is easy to get the wrong connector hooked up to that regulator as there are 3 in close proximity that will fit. You should be able to unhook the hose from the nipple on the rail, pinch that hose closed, and run second hose from the nipple to a bottle. You should not see any fuel in the bottle after cranking.

 

[Toxic]

Did you ever check to make sure the regulator on the rail isn't dumping fuel back into the return while cranking? That's usually what I see is the main problem when the LML trucks aren't building rail pressure. It is easy to get the wrong connector hooked up to that regulator as there are 3 in close proximity that will fit. You should be able to unhook the hose from the nipple on the rail, pinch that hose closed, and run second hose from the nipple to a bottle. You should not see any fuel in the bottle after cranking.

I pulled the line off yesterday and I’m pretty sure I had some fuel coming out when cranking. Tried to get a few videos to confirm but as soon as I’d start cranking my phone would fall over. Valve cover was wet though.